1. Field of the Invention
This invention relates to communication terminal equipment, and more particularly, is applicable to cellular phone equipment of the global system for mobile communications (GSM) standardized in Europe.
2. Description of the Related Art
In recent years, the prevalence of cellular phone equipment is significant, which has been accompanied with a wide variety of functions added to a cellular phone equipment. In addition, not only phone call service is provided from the system side but various additional services have been also provided. With the GSM system as mentioned above, for example, additional services as shown in FIG. 1 are provided. Incidentally, the additional services of the GSM are disclosed in detail in standard literature, such as "European digital cellular telecommunication system (Phase 2): Man-Machine Interface (MMI) of the Mobile Station (MS) (GSM 02.30)", published from the European Telecommunication Standard Institute (ETSI).
As shown in FIG. 1, the additional services in the GSM system include "Number notification", "Non-conditional receive transfer", "Busy receive transfer", "Outside or power-OFF receive transfer", "No-response receive transfer", "Transmit restriction", "International calling transmit restriction", "Except-HPLMN international calling transmit restriction", "Receive restriction" and "Roaming receive restriction".
Out of these, "Number notification" is a service for noticing the phone number of the calling side at the receipt. On the other hand, "Non-conditional receive transfer", "Busy receive transfer", "Outside or power-off receive transfer" and "No-response receive transfer" are all services for transferring the received call to the other communication terminal equipment that has already been registered, divided into four services according to the operating condition of a cellular phone equipment.
Further, "Transmit restriction", "International calling transmit restriction" and "Except-HPLMN international calling transmit restriction", are all services for restricting a calling operation, divided into three services according to three conditions for use of non-conditional, international and except-HPLMN (home country) international calling. Furthermore, "Receive restriction" and "Roaming receive restriction" are all services for restricting a receive operation, divided into two services according to two conditions for use of non-conditional and roaming time (when removed into a service area of other trader and receiving a service) receive.
Such services, however, are usable ordinarily by sending various commands as shown in FIG. 2 from a cellular phone equipment to the base station equipment (to be accurate, the provider side of additional services, what is called, the network side). When a desired service is used, the service setting request command called Activation shown in FIG. 2 is sent. On the other hand, when the use of an additional service is completed, a service completion command called Deactivation shown in FIG. 2 is transmitted. This enables the use of the additional service that has thus far been used to be completed.
Meanwhile, when various types of introduction information concerning additional services are received, an information providing command called Interrogation shown in FIG. 2 is sent. This enables various types of introduction information concerning additional services to be received. When transfer destinations for various transfer services are registered, a registration command called Registration shown in FIG. 2 is transmitted. In addition, when the transfer destination registered is canceled, an erase command called Erasure shown in FIG. 2 is transmitted. This enables the registered transfer destination to be canceled.
Here, a method for the use of additional services by these commands will be described below by referring to embodiments. When using the additional service of "Non-conditional receive transfer", it is only necessary to put the service code (SC: code representing a target additional code) of "Non-conditional receive transfer" shown in FIG. 1 and a supplementary indices (SI: various parameter codes needed for the receipt of additional services) into the command code of Activation shown in FIG. 2 and to transmit them together to the network side.
To be specific, "*" is inputted by pressing the "*" key, then "21", service code (SC) for "Non-conditional receive transfer", is inputted by pressing numeric keys and "*" is inputted again by pressing the "*" key. Next, as supplementary indices (SI), the codes representing the "Transfer destination number", "*" and a -basic service group (BS) are successively inputted and "#", the last code of a command, is inputted. If the send key is pressed after inputting the Activation command of "Non-conditional receive transfer" in this manner, the command code is transmitted to the base station equipment and "Non-conditional receive transfer" is set. After the setting, this enables the additional service of "Non-conditional receive transfer" to be used in this cellular phone equipment.
Similarly, other additional services can be used or terminated for use by entering the control command while referencing the service code and the supplementary index for that additional service shown in FIG. 1, and finally pressing the send key to send the control command.
With such a conventional method for the use of additional services, a user himself must make up the control command of an additional service on the basis of service codes or supplementary indices. This control-command making operation is complicated as seen from the above description, so that errors in making a control command or the like occur, thereby preventing the additional service often from being used. In practice, it is almost difficult for a user to keep all these complicated control commands, service commands or the like in mind and consequently it is natural that errors in mating a command occur.
As a method for solving this problem, it may be thought of to carry a simplified handbook about in which control commands, or service codes and supplementary indices for an additional service are described, but this method is considered to be unfavorable in use for a user and insufficient as a solution.